Question

At a certain temperature the vapor pressure of pure thiophene is measured to be . Suppose a solution is prepared by mixing of thiophene and of acetyl bromide . Calculate the partial pressure of thiophene vapor above this solution. Be sure your answer has the correct number of significant digits. Note for advanced students: you may assume the solution is ideal.

Answer 1

Answer:

0.35 atm

Explanation:

It seems the question is incomplete. But an internet search shows me these values for the question:

" At a certain temperature the vapor pressure of pure thiophene (C₄H₄S) is measured to be 0.60 atm. Suppose a solution is prepared by mixing 137. g of thiophene and 111. g of heptane (C₇H₁₆). Calculate the partial pressure of thiophene vapor above this solution. Be sure your answer has the correct number of significant digits. Note for advanced students: you may assume the solution is ideal."

Keep in mind that if the values in your question are different, your answer will be different too. However the methodology will remain the same.

First we calculate the moles of thiophene and heptane, using their molar mass:

• 137 g thiophene ÷ 84.14 g/mol = 1.63 moles thiophene

• 111 g heptane ÷ 100 g/mol = 1.11 moles heptane

Total number of moles = 1.63 + 1.11 = 2.74 moles

The mole fraction of thiophene is:

• 1.63 / 2.74 = 0.59

Finally, the partial pressure of thiophene vapor is:

Partial pressure = Mole Fraction * Vapor pressure of Pure Thiophene

• Partial Pressure = 0.59 * 0.60 atm

• Pp = 0.35 atm